Seed planting devices are used to deposit or sew individual seeds from a batch of seeds. Such planting devices typically are mechanical devices mounted on or pulled behind a transport vehicle such as a tractor, and the planting devices dispense the seeds in rows as the vehicles traverse large fields. The rate at which individual seeds are dispensed from a planting device is correlated with the speed of movement of the transport vehicle. The deposition rates of seed planters are controlled by various types of metering devices, and are dependent on vehicle speed. For example, a planting device may be set to achieve a desired seed deposition rate as a vehicle traverses a field at about 10 km/hour. In practice, typical modern seed planters deposit individual seeds at a rate between about 10 and about 20 seeds per second. The ability of such planting devices to dispense seeds at a desired and substantially constant rate is critical to farmers and growers in order that a bulk quantity of seeds is evenly and properly distributed over a planting area to obtain a desired yield per acre. Accordingly, proper adjustment and calibration of seed planting devices is important to farmers and growers. In order to properly adjust and calibrate such a planting device, a need exists to properly measure the seed count and frequency in a stream of seeds as the seeds are dispensed from the seed planting device. Because of the rapid feed rates of seed planting devices, however, precise measurement can be difficult.
Seed producers commonly pre-treat seeds and grains before planting in order to enhance one or more attributes of the seeds or grains. Such seed treatments may include applying a treatment coating on the outer surfaces of each seed or kernel, for example. Some surface coating formulations may affect the planting accuracy or planting characteristics of conventional planting devices when such devices are used to plant the treated seeds. For example, treatment coatings may alter the natural surface roughness or smoothness of seeds, or may cause unwanted adhesion between seeds, thereby affecting the interaction between the treated seeds and seed planting devices. Therefore, there is a need to accurately assess the influence of particular seed treatments on the performance of planting devices such that optimal treatment formulations and coating processes can be identified, and such that optimal settings for planting devices can be known for specific types of treated seeds.
Others have explored various techniques and devices for determining the count and frequency of seeds in a stream of seeds. Such devices and methods are used to measure the quantity and frequency of seeds dispensed by a planting device. Such devices also are useful for calibrating and testing seed planting devices to ensure consistent and optimum performance. One such device is a moving grease belt that captures seeds as the seeds are deposited by a planting device. With such a device, the number and spacing of seeds or grains on the belt indicates the effective deposition rate. Unfortunately, grease belt counters are ineffective for measuring the feed rate of large numbers of samples.
Other known measuring devices include electronic measuring systems that utilize infrared sensors or the like to sense the passage of a seed, grain or kernel through a tube or chute as the seed is dispensed from the chute. Unfortunately, known electronic measurement devices typically use single light sensors having limited image-capturing capability. For example, such devices cannot effectively count the passage of two adjacent objects that pass by a sensor substantially simultaneously. In addition, funneling the particles through a narrow tube or chute for counting can influence the flow of particles being measured. Therefore, known electronic measuring devices are not sufficiently accurate, and are unable to provide a sufficiently precise measurement of planting frequency to ensure optimum performance of a seed planting device.
Therefore, there is a need for a seed planting measurement device and method that accurately measures the output quantity and frequency of seed planting devices. Such a device should have a counting accuracy of about 99 percent or greater, and should be capable of distinguishing seeds or grains from smaller dust particles or other small foreign matter commonly found mixed with seeds and grains. Such a device and method also should be capable of capturing data regarding planting frequency as seeds or grains are output directly from a planting device, and without the need for seeds to pass through a restrictive tube or funnel. In addition, the device and method should be capable of measuring the count and frequency of seeds and grains in a rapid stream of seeds or grains having substantial width and depth. For example, the device and method should be capable of counting seeds in a rapidly moving stream of seeds having a stream width and depth that is up to about sixty times greater than the average seed size. In addition, the device should be compact and portable for convenient use in the field.